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

Annotations cover the safety profile (readOnly, non-destructive). The description adds substantive context beyond them: API key requirement, plan-dependent history depth (24h free vs. days up to 90 on Pro), fields nulled on free, and cursor-based pagination. It does not disclose rate limits or ordering edge cases, so it falls short of 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?

Front-loaded with the purpose, followed by routing alternatives, then prerequisites and pagination. Every sentence carries distinct information; no 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?

Covers purpose, alternatives, auth, plan constraints, nulled fields, pagination mechanics, and the response shape (signals[], nextCursor, hasMore, historyDepthDays, plan) — notable because no output schema exists. Nothing an agent needs to invoke this correctly is missing.

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 100%, so the baseline is 3. The description earns extra by explaining plan-dependent semantics for 'days' and the exact cursor convention (pass the last signal ID from the previous page), which the schema states more tersely.

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 ('List signals that have already resolved... newest first, each with its verification outcome'), and explicitly distinguishes itself from three siblings (get_signals, get_signal, get_stats). An agent can pick the correct tool without opening any 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?

Names the routing condition for each alternative: open signals -> get_signals, single signal by ID -> get_signal, totals -> get_stats. The 'already resolved' scope is stated up front, making the when-to-use unambiguous.

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