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

Annotations already declare readOnlyHint=true, and 'Read-only' merely restates that, earning nothing. However, the description does add substantive behavioral context beyond the annotations: it discloses that the response carries a companion 'newest observed build' value and why that value is bundled, which matters because there is no output schema. No auth, pagination, or failure-mode context is given.

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?

The core identification is front-loaded in the first clause. The third sentence ('The observed build rides along because...') is long and somewhat discursive, but it does explain a real semantic distinction that would otherwise confuse the caller, so it largely earns its place.

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 one-parameter read tool with annotations covering safety, the description carries the burden of return-value shape (no output schema exists) and discharges it by naming both the switch and the observed build. It stops short of describing types, field names, or the case where no build has been observed.

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?

There is a single parameter (application_id) with 100% schema coverage, so the schema already documents it fully. The description adds no format, sourcing, or lookup guidance for the id beyond saying 'an Application's', so the 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?

It names a specific verb and resource ('Read an Application's push-to-deploy switch') and specifies the extra payload (the newest build observed on the tracked branch), so an agent knows exactly what this returns. The only gap is that it never names its write counterpart set_application_auto_deploy; the read/write distinction is implied by 'Read' and 'Read-only' rather than stated.

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?

It gives a genuine consultation context: the tool is what you check to tell 'auto-deploy off' apart from 'auto-deploy on with nothing to pick up', which is a real decision point. It does not state when not to use it or point at set_application_auto_deploy/other deployment tools as alternatives, so it is clear context without exclusions.

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