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

Annotations already flag destructive=true, idempotent=false, so the safety profile is covered; the description adds real behavioral context beyond that — removing the last profile auto-pauses the monitor, update_emails replaces rather than appends, an empty list clears the list, and the account email is always retained. It stops short of stating permission/auth requirements or irreversibility of remove_profiles.

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 summary line followed by an action-indexed bullet list; the structure mirrors how the agent must reason (pick action, then supply parameters). Length is justified by eight distinct actions across nine parameters — no sentence is 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?

For a nine-parameter, eight-action mutation tool, the description covers action selection, parameter requirements, prerequisites, side effects, and a conservative alternative to deletion. Return values are handled by the existing output schema and safety by annotations, so nothing material 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?

With 0% schema description coverage, the description carries the full burden and does so: every optional parameter (profile_urls, webhook_url, webhook_secret, additional_emails, activity_types, name, signal_id) is tied to the action that consumes it, including value semantics for activity_types and signal_id's conditional requirement.

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?

Opens with a specific verb and resource ("Change an existing signal monitor"), then enumerates all eight actions so the agent knows the full surface of the mutation. It is clearly distinct from create_signal and delete_signal, and even steers away from delete_signal explicitly.

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?

Gives per-action conditions (which extra parameter each action requires), a decision rule ("Prefer pause over delete_signal when the user may want it back"), and a strict prerequisite chain for signal_id (obtain from list_signals, never by name; optional only when a single signal of that type exists). This is close to exhaustive routing guidance.

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