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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds two useful behavioral details: 'Auth: none required' and 'Errors: unknown id', which are not present in annotations. It also clarifies the return is 'full text'. This adds value beyond the structured metadata without contradicting it.

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 with zero redundancy. The first sentence front-loads the purpose and input source; the second adds auth and error details. Every clause earns its place. Ideal length for a simple fetch operation.

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 tool with one parameter, no output schema, and comprehensive annotations, the description covers the essential operational details: what it does, how to get the id, auth requirements, and error behavior. The return content ('full text') is implied. Nothing an agent needs to call it correctly 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?

The schema has 100% description coverage for the single 'id' parameter ('Document id from a search result'), so the baseline is 3. The description adds concrete examples of id formats ('tool:ethora-app-create', 'doc:auth-map#app-jwt', 'doc:hosted-guide') and explicitly states the id comes from 'search', reinforcing the schema. This extra context justifies a score above baseline.

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 states a specific verb ('Fetch'), a specific resource ('the full text of a documentation section or tool reference entry'), and the source of the identifier ('by the id returned from search'). It clearly differentiates from sibling tools like 'search' by specifying it retrieves content by id, not listing/searching. Examples of id formats further clarify the scope.

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 explicitly ties usage to the output of 'search' ('by the id returned from search'), giving clear context on when to call this tool. It doesn't explicitly state alternatives or when not to use it, but the sibling relationship with 'search' and the clear input contract make usage straightforward. It could have been more explicit about the search→fetch workflow, but the guidance is adequate.

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