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

Annotations already declare readOnlyHint=true, so safety is known. The description adds value beyond that by confirming zero side effects and disclosing the X-License-Key authentication requirement, which the annotations do not cover. It stops short of describing match fuzziness or result ordering, but an output schema is present to carry return shape.

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?

The description is front-loaded with the core operation and the exclusion guidance is compact. The usage sentence mildly overlaps with the opening sentence's enumeration of entities, names, and matching terms, but the redundancy is minor.

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 three-parameter read-only search with a fully documented schema, an output schema, and annotations covering safety, the description supplies the missing pieces: authentication requirement and sibling routing. Only minor behavioral detail such as matching semantics is absent.

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%, with limit, query, and space_id all documented in the schema, so the baseline is 3. The description only loosely reinforces that the query targets entity names and token substrings within a memory space, adding little beyond what the schema already states.

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 names a specific verb and resource: keyword and token search across persistent memory to find entities, names, and matching terms. It is immediately distinguishable from siblings like icx_recall_scoped (natural language recall) and icx_remember (writes).

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?

It states when to use the tool (entity exploration, keyword discovery, locating identifiers) and explicitly names two alternatives with the conditions that select them: icx_recall_scoped for NL questions and icx_remember for writes. Nothing is left to inference.

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