Get an email or meeting

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered; the description adds value beyond that by naming the returned fields and explaining the response_format trade-off ("concise" cuts the summary, "detailed" returns all of it). It does not state what happens for a missing or malformed id, which is the main remaining behavioral gap.

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?

Three compact sentences, front-loaded with the verb+resource and then the return contents, with zero padding or restated title. The response_format clause slightly duplicates the schema, but it is short enough to earn its place as a scannable summary.

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 two-parameter read tool with full schema coverage, complete annotations, and an output schema, everything an agent needs to call it correctly is present: the id source, the format switch, and the return payload shape ("structuredContent {interaction}"). No material gap remains.

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 coverage is 100% and includes an enum with a default, so most parameter meaning is already structured. The description still adds the provenance of interaction_id (list or timeline) and frames response_format as a summary-length dial, which is useful framing even though the schema spells out the 300-character cutoff in more detail.

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?

"Fetches one synced email thread or meeting by id" gives a specific verb, a specific resource (a single interaction, not a list), and the retrieval key. The remaining clauses enumerate exactly what comes back (subject/title, time, AI summary, sentiment, linked records, participants, next steps), so it is clearly distinguishable from heliyos_interactions_list.

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 tells the agent where the required id comes from ("from heliyos_interactions_list or heliyos_records_timeline"), which is real routing guidance for a get-by-id tool. It stops short of explicit when-not conditions or stating that heliyos_interactions_list should be used for browsing rather than this tool, so it is clear context without exclusions.

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