ecg_prepare_placements

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

With no annotations the description carries the full burden, and it delivers solid behavioral context: scoring is against the repo, nothing is persisted, the proposal lives only in process memory, and abandoning it leaves no DB row. It stops short of covering authorization requirements, rate limits, or failure modes.

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?

The purpose and the 'does not store' caveat are front-loaded in the first line, followed by dense but useful detail on candidate fields and the return shape. Nothing is obviously wasted, though the multi-clause enumeration is heavy for the space.

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?

There is no output schema, and the description compensates by naming the return values (prep_id/exchange_id plus a per-candidate classification with matched titles and scores). Combined with the persistence caveat, an agent has enough to invoke and interpret the call; error and permission behavior are unaddressed.

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% and the schema declares only two loosely typed params, so the description must compensate. It documents the candidate shape in detail (required title; optional body, fact_type, entities, confidence 0..1, action with an explicit value list) and notes unknown types are accepted. It leaves session_id unexplained, which keeps it just under a 5.

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 specific verb+resource (score candidate facts, stage a proposal) and immediately scopes it with 'Does not store,' which distinguishes it from the sibling ecg_commit_placements. An agent can tell what it does and what it does not do without opening the schema.

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: staging followed by a commit/discard step is suggested by 'Does not store' and 'Abandoning it leaves no database row,' and the sibling set (ecg_commit_placements, ecg_discard_proposal) hints at the workflow. There is no explicit statement of when to choose this over the commit tool or what prerequisites exist, so it stays at the minimum-viable level.

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