create_ingest_key

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

Annotations only say readOnlyHint=false, openWorldHint=false, idempotentHint=false, destructiveHint=false, which are minimal. The description adds substantial behavioral context: the key is returned ONCE in plaintext, it can send traces/metrics/logs/pings for one monitor and nothing else, every REST call refuses it, and it cannot read or change anything in the account. It also discloses the 90-day expiry cap. This goes well beyond the annotations.

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 dense but every sentence earns its place: scope, permissions, relationship to get_trace_setup, plaintext-once warning, security handling, and expiry behavior. It is front-loaded with the most important fact (requires write scope) and the core purpose. It is slightly long but not bloated; the warnings are necessary for safe use.

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 credential-creation tool with no output schema, the description covers what the agent needs: prerequisites (write scope), the one-time plaintext return, the binding to a monitor, the expiry default, and the security handling. The sibling context (get_trace_setup) is referenced, and the parameter schema is fully covered. Nothing critical is missing for correct invocation.

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 100%, so the baseline is 3. The description adds meaning beyond the schema by explaining the security-critical handling of the returned key, the relationship to get_trace_setup, and the expiry cap behavior. It doesn't add much per-parameter detail beyond the schema, but the context it adds is valuable. A 4 is appropriate because the description enriches the parameters' purpose even though the schema already documents them.

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 states a specific verb ('Create'), a specific resource ('a tracing key for one monitor'), and the exact scope ('ingest-scoped LastPing key bound to that monitor'). It clearly distinguishes this from generic create_api_key by emphasizing the monitor binding and ingest-only permissions, so an agent can tell it apart from siblings without opening the schema.

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 description explicitly says this is the credential get_trace_setup's steps need, tells the agent to omit expires_at for a 90-day key, and warns against using one's own LastPing API key as an exporter's credential. It also gives clear security handling instructions (write to git-ignored file, never echo back). This is explicit when-to-use and how-to-use guidance with exclusions.

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