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

With only destructiveHint=true in annotations, the description usefully adds that the operation is an upsert/replace scoped to the draft (so the destruction is limited to an existing draft spec, not live pipelines) and that it returns the staged row. It does not cover permissions/auth or error behavior on an invalid spec, so it is not fully exhaustive.

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 tight sentences, front-loaded with the WRITE marker and the core action, followed by effect scope and the upsert key. Every clause carries information; no filler.

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 4-parameter tool with full schema coverage and no output schema, the description covers purpose, side-effect scope, upsert identity, and the return value ('the staged row'), which is what an agent needs to call it correctly without inspecting further docs.

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 adds genuinely new semantics by naming the upsert key ('upsert on draft_id,catalog_name'), which the schema does not state anywhere. That key behavior is essential for predicting replace-vs-insert outcomes.

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 ('stage (insert or replace) a catalog spec inside a draft') with an explicit WRITE marker, which distinguishes it immediately from read-oriented siblings like estuary_list_draft_specs and estuary_get_catalog_spec. An agent knows this mutates a draft spec, not a live pipeline.

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?

Gives clear context: use it to stage edits in a draft, and live pipelines are unaffected until publishing, which implicitly routes the agent to estuary_publish_draft for the live-change step. It never names an alternative tool explicitly or states when NOT to use it (e.g. editing a live spec directly), so it stops short of a 5.

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