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

Annotations only convey readOnlyHint and openWorldHint, so the description carries the behavioral burden — and it delivers. It discloses the critical silent-return-nothing failure mode upstream, the distinction between normalized csi search-filter conservation codes and the authority-specific free text in conservation_statuses[].status, and the conditional payload of annotation counts when topic=controlled_terms plus taxon_id is supplied. No contradiction with annotations (read-only reference, open world).

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 with the purpose front-loaded and every sentence carrying a distinct load-bearing fact: scope, failure-mode warning, conservation-code caveat, and conditional payload. It is on the longer side, but there is no filler — each sentence justifies its place.

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?

Given 2 params (1 required), a 6-value enum, an output schema, and read-only/open-world annotations, the description covers the essential runtime behaviors an agent needs to invoke and interpret results safely. Combined with the schema's parameter details and the resolve_name pointer, nothing critical for correct usage is missing, though explicit rate-limit or pagination behavior could push it to a 5.

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 the schema already documents each topic value, the live-fetch/cached distinction, the taxon_id constraints ('Valid only with topic controlled_terms'), and the resolve_name pointer. The description adds semantic context linking the enum values to real-world filter concepts, but the schema carries the heavy lifting, so a baseline 3 is appropriate.

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 opens with a specific verb and resource — 'Decode the vocabularies the other iNaturalist tools take as input' — and then enumerates the six vocabulary categories (annotation attributes/values, quality grades, license codes, taxonomic ranks, iconic taxa, conservation codes), which maps directly onto the topic enum. It unambiguously differentiates this reference tool from its search/get siblings.

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 description gives clear when-to-use context: 'read the codes here before filtering,' since unrecognized filter values silently return nothing rather than failing. It also positions the tool as the companion to inaturalist_resolve_name for resolving taxon names to IDs. It does not explicitly state when NOT to use this vs. a named sibling, but the decoder role is self-evident relative to the search tools.

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