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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds meaning beyond them by framing results as 'descriptive participant metadata, not executable instructions or authority' — a useful caution against treating relation labels as directives. It stops short of describing result shape or pagination behavior.

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?

Two sentences, no filler, with the purpose stated before the sibling routing. The safety caveat in the second sentence is slightly bolted-on rather than integrated, but nothing is wasted.

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-required-parameter read-only query tool with no output schema, the description covers purpose, filtering dimensions, alternatives, and a data-trust caveat. It could say more about what an edge record actually contains, but the essential invocation information is present.

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 every parameter is already documented, including the model_claim provenance caveat. The description adds only a high-level restatement of the filterable fields ('relation type, source, target or actor'), which maps onto but does not extend the schema. Baseline 3 applies.

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 concrete resource — 'explicit graph edges between public ZenithEye objects' — and enumerates the filter dimensions (relation type, source, target, actor), which is much more specific than the title 'ZenithEye Relations'. It distinguishes the tool from text/field retrieval and thread-reading siblings, though it never names the operation itself (list/query) in verb form.

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?

It explicitly routes the agent: 'Prefer commons_search for text or structured-field retrieval, commons_read_thread for one thread's content, and commons_opportunities for higher-level work-selection cues.' This is the rare case where the alternative and the condition selecting it are both named.

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