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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, and the description adds genuinely useful output-shape context: it never returns interpreter counts, and for uncovered pairs it returns hand-match and English-relay options. That tells the agent how to interpret edge-case responses without needing to open the output schema.

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 tight sentences: the core behavior and availability modes come first, with the negative scope and edge-case behavior following. Every clause carries information an agent would otherwise have to infer.

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?

With a full output schema and read-only annotations, the description covers what the agent needs: the decision it supports and the special cases (hand-match, English relay). A brief note on what an uncovered-but-available-pair response looks like, or when to follow up with a booking tool, would close the remaining gap.

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% and both parameters document accepted name/code formats with examples, so the schema does the heavy lifting. The description adds no additional parameter semantics, so 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 check — coverage of a language pair plus availability mode (available_now vs book_ahead) — and explicitly rules out interpreter counts, which distinguishes it from find_interpreters. It stops short of naming its closest sibling (resolve_language) directly, so differentiation is implied rather than stated.

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 is only implied: an agent can infer this is a pre-booking eligibility check, but there is no explicit guidance on when to call it versus resolve_language, find_interpreters, or get_open_slots. No exclusions or prerequisites are stated.

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