UNDERSTANDING — Get a list you own, with each member resolved to its current name, band, and score. Priced B1 (single-entity synthesis) — $0.01 per call under pay-as-you-go; included in Understanding and Influence. See apis://prices.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | List id, as create_list returns it or list_lists lists it. | |
| context | No | Optional: one sentence on why you are asking. Never used to rank; read only if a result is wrong. |
Changes observed during successful MCP inspections.
Input schema / properties / context / descriptionPrevious value: -"Optional: why you are asking. One sentence — the task you are trying to complete, or what you expect to get back. Never included in the answer and never used to rank; it is read only when a result turns out to be wrong, which is when knowing the intent is what makes the report actionable."New value: +"Optional: one sentence on why you are asking. Never used to rank; read only if a result is wrong."Input schema / properties / id / descriptionAdded value: +"List id, as create_list returns it or list_lists lists it."Input schema / properties / contextAdded value: +{
+ "description": "Optional: why you are asking. One sentence — the task you are trying to complete, or what you expect to get back. Never included in the answer and never used to rank; it is read only when a result turns out to be wrong, which is when knowing the intent is what makes the report actionable.",
+ "type": "string"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false). The description adds two genuinely useful facts beyond structured data: the priced tier with cost ($0.01/call) and that members are resolved to live values. It does not contradict the annotations, but operationally it stays shallow.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three short sentences with the purpose front-loaded and no wasted prose. The pricing sentence is slightly tangential but genuinely informative and earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema, the description usefully previews what is returned (resolved name, band, score), annotations handle safety, and the schema handles parameters. Coverage is close to complete, lacking only usage routing.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so both parameters (id, context) are already documented in the schema. The description adds no additional syntax or format meaning for them, making the baseline 3 appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource ('Get a list') plus ownership scope ('you own') and even the resolved return content (each member's current name, band, score). This is clearly distinguishable from list_lists, though the description never names the sibling explicitly.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The 'you own' qualifier implies the retrieval context but there is no explicit when-to-use, when-not-to-use, or pointer to the alternative sibling (list_lists, create_list). The agent must infer that this fetches a single list rather than enumerating lists.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.