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

Annotations already carry the key traits (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the description's only added behavioral signal is that metadata is privacy-filtered. It says nothing about overwrite semantics on an existing investigation, required identifiers or scopes, or retry/idempotency expectations for a tool whose schema includes an idempotencyKey.

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?

A single 11-word sentence with the action front-loaded and no filler. It is efficient, though the internal jargon and awkward grammar ("hosted save investigation") cost it a point.

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 6-parameter mutation with a nested object, an idempotency key, and no output schema, one sentence is not sufficient. The description never clarifies which of projectId / investigationId / sessionId / executionId are needed together or what happens to prior investigation state on update.

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 100%, so the baseline is 3. The description contributes "privacy-filtered project metadata", which loosely points at the `details` object, but it adds no meaning for the six IDs, and it does not correct the schema's obviously reused/wrong descriptions (sessionId, executionId, investigationId and details.status all described as 'Owned project ID').

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 verb ("Update") and a resource ("hosted save investigation"), which is better than a tautology, but "save investigation" is ambiguous — it reads more like 'save an investigation' than 'update a stored investigation record'. No differentiation from siblings such as list_investigations, delete_investigation, or create_finding, so an agent cannot place it in the investigation lifecycle from the text alone.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives. The sibling set contains delete_investigation, list_investigations and create_finding, and nothing here says when this upsert-style write is appropriate versus those.

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