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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds the one thing annotations cannot: an auth requirement (API key with the Signals layer). It says nothing about pagination semantics or result characteristics, so the value added beyond structured data is limited to the auth note.

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 short sentences with no wasted words, and the auth prerequisite is front-loaded. However, the text is telegraphic rather than well-structured — it defines the domain object before stating the operation, and the fragment "Same filters as GET /api/v1/signals" reads as a note rather than guidance.

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 15 optional filters, no output schema, and no documented return shape, the description should at least say what a result contains or how pagination behaves. It does not address results at all, and it leaves the relationship to get_signal and the sibling search tools unexplained, so an agent must open the schema and guess at the rest.

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%, so every one of the 15 filters is already documented in the schema, establishing a baseline of 3. The description's only parameter statement, "Same filters as GET /api/v1/signals, plus severity, confidence and materiality," references an external endpoint the agent cannot inspect and adds no meaning beyond what the schema already provides.

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 defines what a Signal is ("WarStrikes assessments of severity, confidence and materiality") and implies a filtered retrieval, but never states the verb explicitly — no "search/list signals matching filters." It also fails to distinguish this tool from siblings search_events, search_reports, or get_signal, leaving the agent to infer that this is the batch search over signals while get_signal fetches one.

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 only usage guidance is a prerequisite ("Requires a WarStrikes API key with the Signals layer"), which is genuinely useful. There is no statement of when to use this instead of search_events or search_reports, nor when to prefer get_signal for a single record.

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