get-favorite-messages

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

The description discloses some behavioral context by listing the underlying API endpoint ('GET /api/v1/chats/favorite/{chat_id}/messages') and referencing a mirrored function, which implies a read-only GET operation. However, with no annotations, it does not fully describe response format, ordering, pagination behavior, or any permissions needed, so it leaves key behavioral traits undisclosed.

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 description is three sentences, each with a distinct purpose: primary function, API mapping, and usage guidance. It is front-loaded with the main verb/resource, contains no redundant wording, and uses special formatting for code/endpoints to enhance readability.

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?

The description covers purpose, endpoint, and usage distinction, but omits details about pagination behavior (despite page_size/direction parameters), output structure (no output schema provided), and potential ordering semantics. Given that the tool has three parameters and no output schema, the description provides a serviceable but incomplete picture.

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 only 33% (only chat_id has a description), and the tool description adds no parameter-level meaning beyond that. The 'direction' and 'page_size' parameters have no explanation in either the description or schema (beyond enum values and numeric bounds), and the description does not compensate for this gap.

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?

The description clearly states the tool's function: 'Return the favorite (bookmarked) messages for a chat.' It uses a specific verb ('return') and resource ('favorite messages'), and explicitly distinguishes from sibling tools by noting that 'get-messages does not include them' and that this is 'the only way to read starred messages through MCP.'

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 description gives explicit guidance on when to use this tool versus the alternative: 'This is the only way to read starred messages through MCP — get-messages does not include them.' It names the sibling tool directly and clarifies the exact scope difference, providing clear when/to-use guidance.

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