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

The description adds useful behavior beyond annotations: the key is 'fresh', tied to plan tier, and rate-limited to 5/day. However, it does not disclose whether issuing a new key invalidates or replaces existing keys, which is a critical security-related behavior for this type of tool. Annotations already indicate non-read-only, non-destructive, but this gap remains.

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?

Three sentences, all informative and front-loaded with the core action. No filler or redundant restatements of the name or annotations. Each sentence adds value: purpose, use cases, restrictions.

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?

Given the tool has zero parameters and an output schema exists, the description covers the essential aspects: purpose, usage scenarios, plan tier, and rate limit. The only notable omission is whether old keys remain valid, which is important for security but not fully required for basic invocation. The output schema presumably provides return details.

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 input schema has no parameters, and schema coverage is effectively 100%. The description adds no parameter-specific semantics because there are none, and the baseline for zero-parameter tools is 4. It also mentions the key format (ta_data_*), which helps the agent understand what the tool returns.

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 uses a specific verb and resource: 'Issue a fresh ta_data_* API key for your current tenant.' It clearly distinguishes from siblings, as no other tool handles API key issuance. The scope ('current tenant') and key type add precision.

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?

Provides concrete use cases: 'pasting into /add-database or configuring a separate integration.' It implies when to use but does not explicitly exclude alternatives or state when not to use, though no sibling tool directly competes. The rate limit is also mentioned as a constraint.

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