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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the low bar is met by structure alone. The description adds genuinely useful behavior context beyond that: 'Coverage is progressive' warns results may be incomplete/incremental, and it mandates a verification step via read_administrative_document. It does not discuss result ordering or pagination depth, which keeps it from 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 tight sentences, front-loaded with purpose, then filter semantics, then alternatives, then verification. No filler or restatement of the title; each clause carries actionable information.

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?

There is no output schema, and the description compensates by telling the agent to verify results with read_administrative_document and warning that coverage is progressive. Given 5 parameters with weak schema documentation, it could say more about result ordering and page/per_page behavior, but the critical decision inputs are present.

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 only 20% (only search_mode is documented in the schema), so the description must carry the load. It does explain the least obvious parameter well — the meaning of each source_groups enum value and the null/omit case — but query, page and per_page receive no semantic elaboration, and pagination limits go unmentioned.

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 ('Search Spanish tax administrative doctrine') and immediately distinguishes scope from siblings by naming search_decisions for judgments and read_administrative_document for verification. An agent can tell this is a doctrine search tool, not an ID lookup or judgment search, without opening the schema.

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 explicit routing rules: petete for DGT interpretations and binding consultations, dyctea for TEAC/TEAR/TEAL criteria and economic-administrative appeals, omit the filter to search both. It also names two follow-up/alternative tools and the conditions that select them (comparison with judgments, verifying the actual criterion).

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