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

Goes well beyond the annotations by disclosing the cost model (charged per answering source, free when failed/empty/cached, storing and reading free) and that the response reports the credits charged. It also clarifies non-obvious state semantics: the first check is a baseline, and a timed monitor's schedule is not shifted. These are exactly the side effects annotations cannot convey.

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?

Four short sentences, front-loaded with the action, then billing, then baseline, then schedule. Every sentence conveys decision-relevant information; nothing is repeated from annotations or title.

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?

A single-parameter tool with no output schema, yet the description still tells the agent what the return contains (new items, per-source outcomes, credits charged). Billing, baseline behavior and schedule side effects round out everything needed to invoke it correctly.

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?

Only one parameter with 100% schema description coverage ('monitorId from create_monitor or list_monitors'), so the schema already carries the semantics. The description adds no further detail about the identifier format or source of valid values, so 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?

States a specific action (run this monitor's sources now) and specifies exactly what comes back: what is new since the previous check plus each source's outcome. That is clearly separable from the retrieval-oriented siblings like get_monitor_mentions or list_monitors without opening any schema.

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 on-demand semantics (this triggers a run rather than reading stored results) and warns that the first check is a baseline that reports nothing new, which prevents misuse. It never names the alternative for reading historical results (e.g. get_monitor_mentions), so the routing guidance is implied rather than explicit.

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