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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, fully covering the safety profile. The description adds meaningful context by disclosing that the result includes the distribution roll-up and explicitly includes guides with no rendering surface — an inclusion edge case an agent might otherwise not expect. It does not cover pagination, ordering, or performance, though the schema's limit parameter partially addresses volume.

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?

One front-loaded sentence that places the verb and resource first, then adds scope details and the distribution-gap edge case. The parenthetical is dense but informative, and no clause is wasted. Slightly heavy in the middle, but efficient overall.

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 13 optional parameters, 100% schema coverage, an output schema, and read-only/non-destructive annotations, the description plus structured metadata supplies virtually everything needed for correct invocation. The only real gap is explicit routing guidance against the sibling tools, which was already penalized under usage_guidelines.

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 100%: all 13 parameters have rich schema descriptions, including the domain derivation note ('via content/registry/shelves.json') and the 'compact' vs 'full' row-shape distinction. The description itself only loosely maps to the parameters by naming fields (home, status, access, standard) and the roll-up, adding no new syntax, defaults, or format details beyond the schema. 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 verb ('List') and a named resource ('the bicycle.guide registry'), then specifies the exact scope: every guide's home, status, access, standard, syndication and grounding, plus the distribution roll-up, and even the edge case of guides homed to a property with no rendering surface. This precision makes it clearly distinct from siblings get_guide (singular fetch), list_capabilities, and list_taxonomy (different registries).

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?

No explicit when-to-use or when-not-to-use guidance is provided, and no alternative tool is named. The verb 'List' plus the registry resource and the extensive filter parameters imply this is the enumeration/browsing tool versus get_guide for a single record, but that routing is left to inference rather than stated.

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