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

Annotations already declare read-only/idempotent, and the description reinforces this with 'Reads only' and adds an API key requirement and a quality caveat about third-party listings. This adds context beyond the annotations without contradiction.

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 concise and well-structured: purpose first, then usage notes, then caveats and alternatives. Every sentence adds value, with no repetition or fluff.

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 read-only listing tool with zero required parameters, the description covers purpose, usage context, side effects (none), requirements (API key), and quality variation. It is complete for the given complexity, especially with output schema absent.

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?

Input schema has 100% parameter coverage (page, limit, search, category all have descriptions). The description does not add extra parameter-specific detail, but given high schema coverage, the baseline of 3 is 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?

The description clearly states the tool's purpose: browsing marketplace templates. It uses a specific verb ('browse') and resource ('MisarMail marketplace'), and explicitly distinguishes itself from sibling tool list_templates by noting they return different things.

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?

Provides explicit when-to-use ('find a starting point instead of authoring from scratch') and when-not-to-use (lists nothing, installs nothing, suggests inspecting with get_marketplace_item). Clearly directs users to list_templates for owned templates, offering an alternative.

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