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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety and repeatability profile is covered. The description adds only the constraint that evidence is tied to a published signal; it says nothing about result volume, pagination, or what happens when a slug has no linked evidence.

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 front-loaded sentence with no filler or repetition. It is efficient, though very spare for a tool whose routing relative to get_signal could be stated in a few more words.

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?

An output schema exists, so return values need not be described, and the read-only annotations carry the behavioral profile. What remains missing is the relationship to sibling tools and any expectation for slugs without evidence, leaving the definition minimally viable rather than complete.

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 0%, so the schema supplies only format constraints (pattern, length) with no semantic description. The description partially compensates by clarifying that the slug must be for an exact, published signal, which explains the required identifier's meaning but adds no detail about canonicalization or case handling.

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 states a specific verb ("Retrieve") and resource ("canonical evidence events linked to... signal slug"), making it distinguishable from get_signal, which returns the signal itself. However, it does not name or contrast any sibling explicitly, so the differentiation is inferable rather than stated.

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?

There is no guidance on when to use this tool versus get_signal, get_daily_signals, or search_signals, nor any explicit alternatives. The phrase "one exact published signal slug" hints that the slug must resolve to a published signal, but this prerequisite is not framed as usage guidance.

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