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

Annotations already cover read-only and idempotency, but the description adds non-obvious behavior: natural mode is hybrid retrieval requiring vectors and limited to a 50-decision window, the original query is preserved, and retrieval does not establish legal interpretation or exhaustive coverage. Those operational caveats are exactly what an agent needs and are not derivable from the annotations.

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?

It is front-loaded with scope, then routing, then return values, then mode semantics, so an agent can stop reading early. It is fairly long and repeats some search_mode guidance already present in the schema's own description, but no sentence is pure filler.

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?

With no output schema, the description supplies the return shape (identifiers, metadata, official links, indexed excerpts), and it covers the highest-risk parameters and the 50-decision retrieval window. Pagination limits and court-name format are not addressed, which keeps it short of fully complete for a 10-parameter tool.

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 only 10%, so the description must compensate, and it does for the tricky parameters: source_groups enum values and omission semantics, countries ES/EU filtering, search_mode default and interaction with query_intent, and the shape of query_intent usage. It leaves court, page, and per_page unexplained, which is a residual gap but a minor one for a search tool.

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 opening sentence names a specific verb and resource ('Search Spanish and EU court judgments') and even lists the dimensions it can search by. It explicitly states what it does not cover (DYCTEA, PETETE) and names the sibling tool that handles that space, so an agent can separate it from search_administrative_documents without reading schemas.

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 explicit routing: use search_administrative_documents for tax administrative doctrine, use query_intent for required/alternative/phrase/excluded terms, use read_decision to verify literal passages. It also explains when search_mode=strict is required and that query_intent with explicit natural is invalid, so the agent knows both when to use this tool and how to configure alternatives within it.

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