relay_save_fact

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

With no annotations, the description carries the full burden and does well: it discloses that facts are never overwritten, that fork conditions are surfaced in the response, and that credential-like content is rejected at write time. It omits permission/identity requirements and whether a written fact can be retracted, but the core behavioral profile is covered.

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?

Four short sentences, each earning its place: purpose and invariant first, then the linking parameter, then response behavior, then the credential rule. No filler and nothing buried.

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 write tool with no annotations and no output schema, the description covers durability semantics, linking, fork signaling, and a hard input rejection rule. Missing only operational details such as permissions or how to recover from a flagged fork.

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 all four parameters are already documented in the schema, including parent_fact_id's 'omit for a root fact' semantics. The description adds the fork consequence of using parent_fact_id, but otherwise restates what the schema says. Baseline 3 applies.

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?

Starts with a specific verb and resource ('Append a fact to shared memory') and immediately states the append-only invariant, which cleanly separates it from the read-oriented siblings (relay_get_context, relay_get_important_facts, etc.). An agent can identify the operation 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?

Explains the condition for using parent_fact_id ('to say which earlier fact this builds on') and gives an explicit exclusion ('Never store credentials'). It stops short of naming when to prefer this tool over the relay_* read/resolve siblings, but the write-vs-read distinction is clear from context.

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