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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds one genuinely useful behavioral fact: results are capped at the latest 100 runs. It says nothing about ordering guarantees, whether the cap is paginable, or what happens when the contact has no runs.

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?

A single tight sentence that front-loads scope, then the result cap, then a use case. No filler and nothing redundant.

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?

No output schema exists, so the description could reasonably say what a run entry contains, but that is a minor omission. The larger gap is that with 0 required parameters the agent gets no guidance on whether email or contact_id must be supplied, and the hard 100-run cap has no guidance on narrowing via the status filter.

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 67% — email and contact_id are documented and the 'instead of' phrasing signals mutual exclusivity, while the status enum is self-explanatory. The description adds no parameter meaning at all, and notably does not resolve the ambiguity that zero parameters are marked required (can the tool be called with neither email nor contact_id?).

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 verb and resource ('List one contact's runs across all automations'), and the phrase 'across all automations' implicitly separates it from list-automation-runs, which scopes to a single automation. It does not name that sibling explicitly, so the differentiation requires a small inference.

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?

The clause 'e.g. to see which workflows they are in' gives one concrete use case, which is better than nothing. There is no statement of when to prefer list-automation-runs or get-automation-run instead, and no prerequisites or exclusions are given.

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