Edit one flood observation

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

Annotations only carry the safety profile (readOnly=false, idempotent=true, destructive=false, openWorld=false); the description adds genuinely new behavior: PATCH merge semantics, atomic validation against the stored observation, the 400 failure mode with all bad fields named, and the explicit exclusion of photos. This tells an agent what happens on failure and why no half-valid state is stored.

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?

Purpose and mutation mode are front-loaded in the first clause, followed by the two details an agent actually needs (validation failure behavior, photo routing). Slightly prose-heavy wrapping but every sentence carries information.

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 four-parameter mutation tool with an output schema and full annotation coverage, the description supplies the missing pieces: idempotent partial-update semantics, validation/refusal behavior, and where photo attachments belong. Nothing needed to call it correctly is absent.

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%, so the baseline is 3, but the description reinforces the meaning of 'changes' as a merge patch (only supplied fields change, merged with the stored record) and explicitly scopes photos out of the field set, which is not stated in the schema.

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 ('Edit one flood observation') and immediately qualifies it as PATCH-style partial mutation, which cleanly separates it from add_observations, delete_observation, and add_observation_photo_link in the sibling 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?

Explains the operative rule (only fields given change) and routes photos to add_observation_photo_link, which is real alternative-selection guidance. It stops short of stating when a partial edit is preferred over delete+re-add, so it is clear context without explicit exclusions.

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