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

Annotations already indicate read-only, idempotent, and non-destructive behavior, and the description adds valuable context beyond that: no authentication required, 60 requests/minute limit, no pagination, full list returned, site-rating order, and the meaning of rating: null. It also clarifies the rating_status field and source attribution, all of which improve safe and correct invocation.

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 description is dense but every sentence earns its place: purpose, usage routing, auth/rate-limit context, response shape, ordering, null semantics, and attribution. No fluff or repetition.

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 no-required-parameter list endpoint with no output schema, the description is remarkably complete. It covers what is returned, ordering, pagination absence, null-value meaning, rate limits, auth requirements, and how to reference results, so an agent has everything needed to call the tool correctly.

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%: the only parameter, lang, is fully described with its enum values and default. The description does not add parameter-specific semantics, but it does not need to since the schema already carries the burden.

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 clearly states the tool returns a full list of MFO catalog companies with NBU licenses, including rating, review count, and canonical_url. It explicitly distinguishes itself from sibling tools like get_mfo, get_reviews, search_offers, and list_categories by naming what each is for.

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?

Usage guidance is explicit: use list_mfo to obtain slugs for get_mfo/get_reviews or to get a market overview, use search_offers for amount/term matching, and list_categories for thematic collections. This gives the agent clear routing rules with no ambiguity.

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