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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the data is 'live,' it is aggregate-only, and it carries a privacy guarantee that no agent is named or ranked. It stops short of stating refresh cadence or rate limits.

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 dense clauses, front-loaded with the core return value and immediately followed by the aggregate/privacy constraint. Every phrase carries information; nothing is restated from the title.

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?

With no output schema, the description must carry the return-value burden, and it does: it names the three metric families plus the trend series. It leaves minor ambiguity about count formats and what 'probed hosts' means, but nothing that would cause a mis-call of this single-optional-parameter read tool.

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?

There is one parameter and schema coverage is 100%, so the schema already documents 'include_trend' and its default. The description's 'with a daily trend' hints at the trend concept but never states it is optional or parameter-controlled, adding no syntax or semantics beyond the schema — the 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?

States a specific verb and resource ('Returns the live, read-only Agent Continuity Index') and then enumerates exactly what the index contains: memory mentions, memory infrastructure counts, and A2A Agent Card adoption, with a daily trend. That level of specificity implicitly separates it from test-contract and proof-verification siblings, which do not return aggregate metrics.

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?

Usage is only implied: the description tells the agent what the tool returns but never says when to reach for it versus the sibling tools, nor does it name an alternative for per-agent data. The caveat 'Aggregates only; no agent is named or ranked' does bound expectations and implicitly signals a when-not condition, which lifts it above a bare 2.

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