Catalog (freely callable)

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

With annotations already covering read-only/idempotent/no-destructive, the description still adds substantial context beyond structured fields: members are never count-capped, no per-region detail route exists, and a ~40 KB serialized budget errors rather than truncating. That last point is a genuine behavioral trait an agent must plan around.

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?

Front-loaded with purpose, then row shape, then the pagination/budget caveat. Dense but each clause carries operational value; only the back-ticked field enumeration is mildly redundant with the output schema.

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?

Output schema exists, so return values need not be restated, yet the description still flags pagination via next_offset and the hard budget ceiling. Nothing an agent needs to call this 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?

Schema coverage is 100% (baseline 3), and the description adds meaning beyond the schema by explaining why limit matters (the ~40 KB budget errors out rather than dropping data) and tying offset to following next_offset.

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 and resource ('List TiresVote market regions') and immediately frames its role as 'the reference for region filters,' which cleanly separates it from siblings like tires_list_brands or tires_list_sizes that enumerate different catalogs.

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 when to use it ('resolve a market name into a slug instead of guessing') and how to bound results, but stops short of naming a specific alternative tool for other lookup needs.

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