spidra_usage

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

The annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds meaningful context beyond annotations by specifying the scope ('this account's'), the nature of usage (request/credit/token), and the breakdown granularity (day/week). It doesn't disclose return format or limits, but with annotations covering the safety profile, this is sufficient.

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 two sentences, front-loaded with the core purpose and then a clear use-case statement. Every sentence earns its place; no filler or unnecessary detail. It is exceptionally concise while remaining informative.

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 simple tool with one optional parameter, no output schema, and no nested objects, the description covers the what, when, and scope. It lacks an explicit description of return format, but without an output schema, the burden is moderate. The use-case framing ('remaining headroom') adds practical context, making this adequately complete for an agent to invoke correctly.

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%, with the single 'range' parameter fully documented in the schema (enum and default). The description adds no additional parameter-specific meaning beyond repeating the day/week granularity already in the enum. Since the schema does the heavy lifting, a baseline score of 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 clearly states the tool's function: 'Get this account's request/credit/token usage broken down by day or week.' The verb 'Get' and resource 'usage' are specific, and the breakdown by day/week adds clear scope. It also distinguishes from sibling tools, which are all scraping/crawling operations.

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?

Explicitly states when to use: 'Use it to answer "how many credits have I used" style questions or to check remaining headroom before a large batch/crawl.' This gives direct usage context and implicitly separates it from the scraping/crawling siblings, making the intended invocation clear.

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