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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds a real prerequisite ('Requires Keeploop Pro') that the annotations cannot express, but says nothing about result volume, cross-source aggregation behavior, or what an empty result means.

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?

Telegraphic and front-loaded: the core action leads and each following clause covers a distinct concern (status, route, plan gating). Slightly clipped phrasing ('route lists only the monitors carrying that route') costs a little readability but wastes no 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 explained, and the Pro gating plus status/route semantics cover most of the surface. The unexplained mine_only parameter is the remaining real gap for a tool with 0% schema description coverage.

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 0%, so the description is the only documentation source. It enumerates the status values (active default, paused, cancelled, expired, all) and explains the route filter, adding genuine value — but it is silent on mine_only, leaving one of three parameters completely undocumented.

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?

Uses a concrete verb+resource ('List monitors') and adds scope ('on every source'), which is more than a restated title. It does not explicitly contrast itself with read-oriented siblings like check_monitor, so the agent has to infer that this is the bulk-listing tool rather than a single-item lookup.

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?

Explains the status vocabulary and that route narrows to monitors carrying a given route, with a helpful pointer to check_route. However, it never states when to pick this over check_monitor or update_monitor, and there are no explicit exclusions or prerequisites beyond the Pro note.

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