Get Participant

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuine interpretive context beyond that — that a zero referralCount is consistent with CREDIT_AWARDED, and that approved/status/isFulfilled record fulfillment marking rather than delivery — which prevents real misreads of a participant record.

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 sentences, purpose front-loaded, no filler. The middle sentence on referral/reward field semantics is dense and arguably overlaps the output schema's territory, but it is not padding.

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 an output schema present the description needn't explain return shape, and annotations cover the safety profile, so the remaining job is purpose, lookup keys and targeting — all covered. Only the missing routing guidance against siblings (list vs get vs analytics/activity logs) and not-found behavior keep it from a 5.

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 only 33% (participantId and participantEmail are undocumented in the schema). The description compensates by stating both identifiers work as lookup keys and by restating the campaign targeting rule ('targets campaignId if you pass it, otherwise GROWSURF_CAMPAIGN_ID'), covering all three parameters meaningfully.

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?

Names a specific verb (Fetch), the resource (a single participant), and both lookup keys (participant ID or email address). The word 'single' implicitly separates it from the sibling growsurf_list_participants, so an agent can route without opening the schemas.

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 — 'single participant' hints this is the targeted-fetch counterpart to list_participants, and the campaign-targeting sentence gives a calling context. There is no explicit when-to-use/when-not statement and no named alternative such as list_participants or get_participant_analytics, which matters given the large sibling surface.

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