MCP RAG Search

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful operational facts not in the annotations: the group, the POST endpoint, and the 10-credit Tier 1 cost. It stops short of describing what scoring means, whether results are ranked or truncated, or what the chunks contain.

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?

The text is short and the one substantive sentence is front-loaded, so nothing is padded. However the bracketed metadata lines consume most of the definition's budget while the actual purpose is left as a fragment, so brevity comes at the cost of substance rather than from efficiency.

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?

An output schema exists, so return values need not be explained. But this is a nested-object, cost-bearing retrieval tool with an undocumented topK and query, and the description leaves open whether results are ranked passages, tags, or chunk IDs. That is not enough for an agent to call it with confidence.

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 33%: the nested chart object is well documented in the schema, but topK and query carry no descriptions anywhere. The description only restates "Required: query, chart", which duplicates the schema's required list, and says nothing about what topK controls or what a good query looks like (2-400 chars).

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?

"Keyword-tag scoring over chart chunks" conveys the general operation (a scored retrieval over chart data) but is a noun phrase rather than a verb+resource statement, and never says what a caller gets back or how it differs from retrieval-flavoured siblings such as astroway_reference_natal_texts. The endpoint and cost lines add operational framing but not purpose.

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?

There is no when-to-use or when-not-to-use guidance, no mention of alternatives, and no prerequisites beyond the required-parameter list. With hundreds of siblings in this namespace, an agent has no signal for choosing this RAG search over a reference-text or interpretation tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.