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

Annotations already mark readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds behavioral context by enumerating what 'full detail' includes (person, ICP analysis, why-it-matters, suggested opener, talking points), which tells the agent the kind of information it can expect. No additional traits like rate limits or errors are mentioned, but none are critical for this simple read operation.

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?

A single sentence that front-loads the action ('Fetch one signal by id'), states the scope ('full detail'), and then lists the detail components without waste. Every part earns its place and there is no redundant elaboration.

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?

The tool has an output schema, so return values are documented elsewhere. The description provides enough context about what the tool does (single signal fetch, full detail) and what the one parameter means (id). Given the low complexity and the presence of output schema and annotations, nothing essential is missing for correct invocation.

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% and the parameter id is described in the schema as 'The signal id.' The description only repeats that the tool fetches by id and does not add format, example, or source information beyond what the schema already provides. According to the calibration, baseline 3 is appropriate when the schema carries the full semantic load.

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 uses a specific verb ('Fetch') and clearly identifies the resource ('one signal by id') with the exact scope of detail ('person, ICP analysis, why-it-matters, suggested opener, talking points'). It differentiates itself from list_signals and other siblings like get_person_intelligence by emphasizing a single signal with full detail, so an agent can select it without opening 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 context is clear: this is for fetching a single signal when the id is already knownibus. It does not explicitly say 'use list_signals for multiple or filtered signals' or mention when not to use it, but the phrase 'one signal by id' clearly implies the appropriate scenario. No explicit exclusions or alternatives are provided.

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