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

Annotations already cover readOnly/idempotent/destructive safety, so the bar is lower. The description adds genuinely new behavior: the content is served from R2, it does not fetch GitHub, it inherits the listing page's visibility, and it returns 404 when nothing was stored. It stops short of describing response format or body size, but the visibility and failure semantics are useful additions.

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 core gating condition is front-loaded and the sentences are short and information-dense. There is mild redundancy, since the 'call only when `readme_api` exists' rule appears early and is restated at the end, but nothing is wasted.

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 simple read-only fetch of a stored document, the description covers origin, visibility, the 404 failure case, and the gating precondition. With no output schema, it could say more about what the README payload looks like (format, size), but the operational essentials are present.

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 coverage is 100%, so both `id` and `retry_key` are already documented in the schema. The description adds no syntax or format details about the parameters beyond what the schema provides, so the baseline 3 applies.

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 resource (the collected project README for a listing) and clarifies its origin (R2 bucket `mural-coleta`), which is more specific than the title alone. However, it does not explicitly name a sibling it replaces or contrast with `get_listing`, so routing relies on inference rather than explicit differentiation.

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?

It gives an explicit, actionable precondition: call it only when `get_listing` includes `readme_api`, and warns that a page without that field has no README and the route answers 404. This is a clear when-to-use and when-not-to-use rule tied to a sibling tool.

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