mdl_custom_lists_edit

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, non-idempotent), so the bar is lower, and the description still adds two useful facts beyond structured data: host-configured MyDramaList authentication is required, and 'fields' behaves as an upstream patch object (partial update). It stops short of describing error behavior or what happens to omitted fields.

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?

Front-loaded with the purpose, good. But it spends two sentences restating the same idea about 'fields' — 'an upstream patch object' and 'a JSON object of upstream parameters' — which is redundancy rather than added information.

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?

For a two-parameter mutation with no output schema and 0% schema coverage, the essentials (auth, explicit-request guardrail, partial-patch semantics) are present. Missing are the required list_id semantics, the full set of editable fields, and any failure/response behavior, so an agent could still call it incorrectly.

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 0%, so the description has to carry the load. It explains 'fields' as an upstream patch object with name/description examples, but 'list_id' (the only required parameter) is never characterized, and 'upstream parameters' remains vague about the accepted keys.

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 ('Custom Lists: edit') and names the payload shape and example fields (name, description). It is clearly distinguishable from sibling mutations like mdl_custom_lists_create or mdl_custom_lists_delete, though it never explicitly contrasts with them.

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?

Gives one real guardrail: 'use only for an explicit user request,' which tells the agent not to fire this autonomously. However, it names no alternatives (create/delete/add_item/set_votes) and gives no prerequisite or precondition beyond the auth note, so the routing guidance is only implied.

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