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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds genuinely new behavior: content is returned as Markdown, unknown routes are rejected, and legal pages ignore the language parameter.

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 compact sentences, front-loaded with the core action and followed by the routing rules. Every clause carries information an agent needs.

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?

There is no output schema, and the description does state the return format (Markdown), so the main gap is closed. It does not describe failure behavior for unknown routes beyond the prohibition, nor any size/pagination characteristics, but nothing essential for a correct call is missing.

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 carries the burden, and it does: 'route' is sourced from list_sections with '/' as the homepage special case, and 'language' is optional with an English-only restriction for legal pages. The 80-character route cap is left undocumented, which is minor.

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 (fetch) and resource (a single published guide) plus the return format (Markdown). It is clearly distinguishable from the list_* siblings, which enumerate collections rather than retrieving one item.

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?

Explicitly tells the agent where the 'route' value comes from (list_sections) and that '/' fetches the homepage, which is real routing guidance. It stops short of stating when not to use this tool, but the constraint 'Only known public guide routes are allowed' bounds usage well.

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