sf_api_usage

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

With no annotations, the description carries the full burden, and it does well: it discloses that the tool reads the Sforce-Limit-Info header when available, avoids an extra request, and falls back to /limits otherwise. It does not describe the exact output shape, but the read-only, no-side-effect nature is clear.

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 first sentence front-loads the main purpose, and the second adds only the implementation/fallback detail that matters for understanding cost and behavior. Every sentence contributes; there is no fluff.

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 zero-parameter, read-only info tool, the description is nearly complete: it explains what is reported, the source of the data, and the fallback edge case. It does not specify the return fields or format, which would be a small improvement given there is no output schema.

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 tool has zero parameters and an empty input schema, so there is nothing for the description to add about argument semantics. The 0-parameter baseline applies, and the description correctly focuses on behavior instead.

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 ('Report') and resource ('Salesforce REST API usage against the org's daily limit'), making the tool's purpose unambiguous. It also differentiates from sibling CRUD/query/search tools, none of which report API quota consumption.

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 clearly frames when the tool is useful: checking current API usage against the daily limit. It also explains the conditional behavior (header vs /limits fallback), but it does not explicitly contrast it with a similar sibling such as sf_org_health or state when not to use it.

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