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

With no annotations the description carries the full burden, and it does disclose meaningful behavior: fallbacks are applied, a source citation and data freshness are included, and the us-gsa fiscal-year selection rule is spelled out (FY2026 vs FY2027 windows). It stops short of stating permission requirements, rate limits, or error behavior.

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 dense sentences, front-loaded with the core purpose and return payload, with the regime-specific rule trailing. Slightly packed but no filler; every clause adds information an agent would otherwise have to guess.

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?

An output schema exists, so the description does not need to explain returns, yet it complements them with freshness, citation, and fallback behavior. The one remaining gap is how the optional locator parameters (city vs. state vs. postal_code) interact, which is left entirely to the schema.

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 the baseline is 3, but the description adds real semantics beyond the schema: the us-gsa date-to-fiscal-year mapping (FY2026: 2025-10-01..2026-09-30) is not derivable from the fields, and the fallback note clarifies how an unlisted city resolves.

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 ('returns the lodging and meal allowance') and pins the scope to 'one location under one regime', which cleanly separates it from search_per_diem_locations and calculate_trip_allowance. It goes further to enumerate what comes back (regime breakdowns, fallbacks, citation, freshness), so an agent knows exactly what this call yields.

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?

The 'one location under one regime' scoping implies the lookup use case, but there is no explicit when-to-use/when-not guidance and none of the sibling tools are named as alternatives. An agent must infer that this is the single-point lookup rather than the search or trip-total tool.

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