Read emailmd docs

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

No annotations, but description fully conveys it's a read-only fetch operation with no side effects. Transparent about external call. Could mention error behavior but acceptable.

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?

Two sentences: first defines purpose, second adds usage details. No wasted words, front-loaded.

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?

Given one optional parameter and no output schema, description covers key behaviors. Lacks mention of response format, but not critical for a documentation tool.

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 covers parameter description (100% coverage), and description adds practical examples ('buttons', 'frontmatter', 'theme', 'directives/hero') and context for usage.

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?

Description clearly states 'Fetch emailmd documentation from emailmd.dev', specifying the verb (fetch), resource (documentation), and source. Distinct from sibling tools lint and render.

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 explicit usage: call with no arguments for index, pass page for specific page. Also advises reading relevant page before using uncertain syntax. Lacks explicit when-not-to-use but sufficient.

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