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

Annotations already declare readOnlyHint, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds genuinely useful context beyond annotations: it returns name comparisons but not values (a privacy property), and it is free with no key/credits/wallet. It does not disclose pagination or size-limit behavior, keeping it below a 5.

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 clauses, front-loaded with the core comparison and the values-not-returned guarantee. 'Existing source and input limits apply' is vague filler, slightly diluting an otherwise tight statement.

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?

An output schema exists, so return-shape explanation is unnecessary, and the description covers the privacy guarantee, cost, and legacy-field implications. For a 3-param comparison tool this is nearly complete; only pagination/limit specifics are left implicit via 'existing limits apply'.

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 67%. The two meaningful inputs (template, actual) are self-explanatory from their names, and the two legacy fields carry their own 'ignored in free mode' descriptions in the schema. The description's note that no key/credits are needed reinforces the legacy-field behavior, but adds no format or semantic detail for template/actual.

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 ('Compare environment-variable names against a template') and immediately names the key exclusion ('never returns assignment values'). This distinguishes it from sibling audit/scan tools like security_secret_scan and agents_config_audit without needing their schemas.

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?

Usage is implied by 'Compare ... against a template', but there is no explicit when-to-use or when-not-to-use versus the many sibling comparison tools (e.g., commerce_variant_compare, data_json_diff, agents_tool_name_conflicts). The 'FREE during validation' note hints at a workflow stage but does not name an alternative tool.

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