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

No annotations are provided, so the description carries the full burden, yet it adds nothing behavioral: no statement that this is a read-only lookup, no note on whether partial/fuzzy location names return multiple matches (the schema's openapi_examples show a 'toky' partial match, but the description is silent), no mention of the optional date's effect on results, and no indication of response shape.

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?

At six words there is zero waste and the key is front-loaded, but the brevity is under-specification rather than efficiency — the single fragment cannot carry the routing or behavioral load this tool needs.

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 4-parameter tool with no annotations and no output schema, the description leaves too much unsaid: the meaning of DSSR versus GSA/DTMO/FEMA per diem, whether results are single or multiple, and how the optional date and verification_url change output all go unexplained.

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 schema already documents location, country_iso_code, date, and verification_url thoroughly, including the ZZ special case and the get_countries resolution hint. The description's only contribution is the phrase 'by location name', which is redundant with the schema. 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 fragment 'DSSR per diem by location name' names the resource (DSSR per diem) and the lookup key (location name), which is enough to guess it returns per diem rates for a location. But it is not a full sentence, never expands the DSSR acronym, and never states what is actually returned (rates, allowances, lodging/meals breakdown), so an agent cannot cleanly separate it from siblings like get_perdiem_allowance, get_allowances_by_location, or get_dssr_locations.

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?

There is no when-to-use guidance, no exclusions, and no mention of any alternative. With over 40 siblings, including several near-identical per diem lookups (by_postcode, get_gsa_perdiem_by_destination, get_dtmo_perdiem_conus), the absence of routing guidance is a real gap.

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