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

The annotations already establish the safe-read profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the description is not required to carry safety disclosure. It adds real value beyond that by warning that results may contain end-user personal data and instructing minimal quoting and identifier masking, plus noting cursor-based pagination. It does not mention rate limits or ordering/stable-sort behavior, keeping it below 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?

Two sentences, both earning their place: the first states what the tool does and its scope, the second is an actionable handling constraint. The purpose is front-loaded and there is 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?

An output schema exists, so return values need no explanation, and annotations handle the safety profile. With 8 parameters fully documented in the schema, the description supplies the two things structured data cannot: the PII-handling obligation and the pagination model. The main remaining gap is the absence of sibling routing (list vs. single fetch, list vs. search).

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 parameter (limit, range, cursor, reason, user_id, agent_name, user_intent, namespace_id) is already documented in the schema. The description only gestures at 'API filters and cursor pagination' generically, adding no syntax, defaults, or interaction detail beyond the schema. Baseline 3 applies.

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 and resource ('List signals') and scopes it to 'one Flowlines namespace', which is concrete enough for an agent to act on. It stops short of naming or distinguishing itself from siblings such as get_signal (single-signal fetch) or search, leaving the list-vs-fetch boundary to inference from the verb alone.

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 explicit when-to-use or when-not-to-use guidance, and no alternative tool is named. 'Using API filters and cursor pagination' hints at how to page through results but says nothing about when this tool is the right choice versus get_signal, aggregate_sessions, or search.

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