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 the triggers/scope of failure content, but 'Recent' is left undefined — no time window, no cap on how many failures return, no indication of rate limits or logging prerequisites.

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 short sentences, zero filler. The return content is front-loaded and the usage trigger follows immediately, with nothing redundant with the 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?

With no parameters and no output schema, the description carries the return-value burden well by naming the failure records and their trigger fields. The undefined recency window is the only real omission for an agent deciding whether this call will surface the failure it cares about.

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?

The tool takes zero parameters, so there is nothing for the schema to describe and no semantic work for the description to do. Baseline 4 applies; the scope limitations that a hypothetical filter parameter would carry are instead partly addressed by the 'Recent' wording.

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 resource and return content: recent rules.js failures plus the event or day that triggered each. That is far more useful than the name 'get_errors' alone. It doesn't explicitly differentiate from the sibling get_logs, which is the main gap.

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?

"Read this when a slot looks wrong" gives a concrete diagnostic trigger, which is real when-to-use guidance rather than an implied generic 'get errors'. It stops short of naming an alternative (e.g. get_logs) or stating when not to reach for it.

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