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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: state-only results are paginated and capped at 25 per call, and the fiscal-year window (Oct 1 – Sep 30) is disclosed. Return-shape detail is also present. Rate limits and cost hints are absent, keeping it short of a 5.

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?

Four dense sentences, all front-loaded: purpose and scope first, then input selection, then pagination, then temporal/geographic caveats. No filler and nothing redundant with the 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?

No output schema exists, but the description lists what is returned (12 monthly lodging limits, daily M&IE, locality/county coverage, source metadata), and covers pagination and scope limits. The main gap is the unmentioned relationship to gsa_per_diem_mie_breakdown for agents wanting a breakdown view.

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%, so the baseline is 3 and the schema carries the per-field syntax. The description adds meaning beyond the schema by defining the fiscal-year boundary and the CONUS-only geographic constraint, which the schema fields alone do not convey.

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 ("Look up official GSA lodging and M&IE reimbursement rates") and pins the scope to federal fiscal year + CONUS destination. An agent can tell it apart from most lookup siblings, but the description never mentions the related gsa_per_diem_mie_breakdown tool, so it doesn't fully differentiate within its own family.

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?

Gives concrete input selection rules ("Provide either a five-digit ZIP, or a two-letter state with an optional city") and clear scope exclusions (Alaska, Hawaii, territories, foreign locations use other sources). It stops short of naming an alternative tool, so it lacks the explicit when-to-use-this-vs-that routing that would earn a 5.

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