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

The annotations only declare readOnlyHint, and the description adds substantial operational context beyond it: status is derived at query time, the API key must hold the 'declarations' entitlement, and the error-vs-empty-result semantics are spelled out ('an empty response never means not entitled'). This is exactly the kind of behavioral disclosure that prevents an agent from misinterpreting results. It does not contradict the read-only annotation.

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?

Very compact and front-loaded: the first sentence states the purpose, the second scopes filtering and pagination, the third clarifies status derivation, and the final sentence covers the entitlement/error nuance. Every sentence earns its place with no filler, and the critical caveat about empty-vs-error is placed as a deliberate closing note.

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 seven parameters, zero enums, 14% schema coverage, and no output schema, the description leaves significant gaps: filter-value semantics are unexplained, and there is no mention of return shape, default page size, or date formats. The operational side (auth, error semantics, status derivation) is well covered, but for a browsing tool with heavily undocumented filter parameters, the missing semantics materially hinder correct invocation.

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?

With schema description coverage at only 14% (only cursor is documented in the schema), the description bears the burden for the other six parameters. It does explain keyset/cursor pagination, which aids understanding of limit and cursor, and notes that record status is derived at query time. But it never explains what status, active_on, jurisdiction, disaster_type, or instrument_type accept — formats, permitted values, or semantics are entirely absent.

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 verb-resource pair ('Browse and historically report on declaration records') that clearly positions this as the general collection-listing tool, in contrast to lookup-shaped siblings like declaration_by_agrn, declarations_by_point, and declarations_by_postcode. The filter/pagination mention reinforces the list scope. However, it never explicitly names the sibling alternatives, so differentiation relies on the reader's inference.

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?

No explicit when-to-use or when-not-to-use guidance is given. The description never names alternatives like declarations_by_point or declarations_by_postcode for location-based queries, nor declaration_by_agrn for single-record lookups. The 'browse/report' framing implies general listing, but an agent is left to infer which tool to route to.

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