Corpus Overview — Start Here

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

Annotations already establish safe read-only, idempotent behavior. The description adds value beyond this by detailing the contents of the response (domains, categories, tool pointers, identifiers, bulk-ingest URLs), giving the agent a clear picture of what the 'map' includes. No contradictions or hidden caveats.

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?

Two sentences with dense, relevant information. The key directive 'start here' is front-loaded, and every detail describes the returned content without filler. This is exemplary conciseness for a complex structural overview.

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 zero-parameter tool with an output schema, the description is fully self-contained. It explains what domains are covered, what categories are inside, how to select retrieval tools, and what auxiliary data is included. The agent can correctly decide to invoke this tool and know exactly what to do with the result.

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?

The tool has no parameters, and the schema covers 100% (vacuous). Per the rubric, 0 params warrants a baseline of 4. The description adds no parameter information because none exists, which 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 clearly states the tool's purpose: 'Get the corpus map' and enumerates exactly what it returns (domains, categories, pointer to retrieval tools with expected identifiers, languages, licence, bulk-ingest URLs). It also explicitly labels it as the starting point, distinguishing it from sibling list/get tools.

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 phrase 'start here' gives explicit usage timing, and 'One call is enough to know exactly where to go next' explains how to use the tool to navigate to other tools. It indirectly differentiates from siblings by explaining that it tells you which tool retrieves a unit.

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