Erinys Update

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

No annotations are supplied, so the description carries the full burden. It does disclose genuinely useful PATCH semantics ('only provided fields are changed'), but omits whether null means 'clear the field' or 'leave unchanged', whether the id must exist, and what errors/permissions apply to a mutation.

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 short sentences, front-loaded with the action and followed by the key behavioral qualifier; nothing is padded. It is efficiently written but arguably too terse for a 7-parameter mutation.

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?

A return-value description is unnecessary since an output schema exists, which lowers the bar. However, for a mutation tool with no annotations and zero parameter documentation, the description leaves too many gaps — field-clearing semantics, failure modes, and sibling routing — to be considered complete.

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 0% across 7 parameters, so the description must compensate and largely does not. Beyond implying that id identifies the target and all other fields are optional, it says nothing about type, scope, metadata (merge vs replace), or the null-handling ambiguity baked into the schema defaults.

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?

The description names a specific verb ('Update') and resource ('an existing observation'), and adds that this is a partial update. It never distinguishes itself from siblings like erinys_supersede (replacement) or erinys_reinforce, so an agent cannot tell which mutation tool applies without comparing 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?

There is no statement of when to use this versus erinys_save (create), erinys_supersede (replace), or erinys_forget. The only contextual hint is that a record must already exist, which is implied by 'existing' rather than stated as a precondition.

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