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

Annotations already establish readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral context: it is parameterless, it measures a fixed 24h window, it reports dead account feeds, and it returns age_seconds values. It does not describe rate limits or error behavior, but the added detail is substantial.

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 tight sentences with no filler: the first defines scope and outputs, the second gives the triggering conditions. The most decision-relevant framing ('tell no data from stale data') is saved for the end where it lands as the payoff.

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?

There is no output schema, so the description must carry the return-value burden and does: freshness verdict fields (stale, age_seconds) and source coverage. Combined with the annotations covering the read-only/open-world profile, an agent has everything needed to call it correctly and interpret the result.

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?

Zero parameters, which is the baseline-4 case; the description explicitly confirms 'No parameters', removing any doubt an agent might have about required inputs.

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 ('Live health of the TweetFeed pipeline') and then enumerates the two outputs: a per-artifact freshness verdict (stale, age_seconds) and source coverage over a 24h window. This is clearly distinguishable from the sibling lookup/query tools (check_hash, query_iocs, search) because it reports on pipeline health rather than on indicator data.

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?

Gives explicit trigger conditions: call it before trusting a feed pull, or when a lookup returns nothing, to distinguish 'no data' from 'stale data'. It covers when to use but names no alternative sibling or when-not condition, so it stops just short of a 5.

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