add_decision

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

No annotations are provided, so the description carries the full burden. It does disclose one real behavioral trait — the record is persisted with the project and outlives the session — but says nothing about whether this is an append-only write, whether duplicates are allowed, permissions required, or what the call returns.

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 tight sentences with zero waste; the core action and captured content come first, with the persistence rationale as supporting context.

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 five-parameter mutation with no annotations and no output schema, the description covers intent and persistence but leaves success/failure behavior and the return value unstated. Adequate to call it, not sufficient to predict what comes back.

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 80%, so the schema already documents title, reason, decision, and alternatives almost verbatim. The description restates the same what/why/alternatives framing and implies the project binding, but adds no format, length, or optionality guidance beyond the schema (projectId is not discussed at all).

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 (record) plus the resource (a design decision for a project) and enumerates the content it captures: what was chosen, why, and rejected alternatives. That is enough to separate it from list_decisions without opening a schema, though the sibling is never named.

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 — an agent infers 'call this when a design choice is made' from the verb and the durability line. There is no explicit when-to-use, no prerequisite (e.g., project must exist), and no pointer to list_decisions for reading them back.

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