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

Beyond the readOnlyHint annotation, the description explains crucial behavior: values are never returned, apply_state has meaningful values, requirements_state governs how to interpret missing_keys, and unknown requirements_state means the Application's needs could not be established. This is unusually complete behavioral context for a read-only tool.

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 description is long but front-loaded and structured around the returned fields, the interpretation caveat, and the primary use case. Every sentence largely earns its place, though the final 'Read-only' restates the annotation and the density is higher than strictly necessary.

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 output schema, the description carries the full burden of explaining return values, and it does so by naming secret_names, apply_state, requirements_state, missing_keys, and unfilled_secrets. It also explains how to interpret those fields, leaving no significant gap for an agent calling this tool.

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 coverage is 100% and there is only one parameter, application_id, which the schema already describes as 'The Application's id.' The description adds no additional meaning about that parameter, so the baseline 3 is appropriate.

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?

The description opens with a specific verb and resource: 'Read the environment secrets an Application's generated manifests declare.' It distinguishes this from generic secret-reading routes by stating that values are never returned, which clarifies exactly what kind of secret information this tool exposes.

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 concrete trigger for use: 'This is the read to reach for when a deployed Application crashes on startup or reports missing configuration.' It does not name a specific alternative tool to use instead, but the use case and the warning about reading requirements_state first provide strong contextual guidance.

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