set_feature_context

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

With no annotations provided, the description carries the full burden and largely meets it: it discloses that the tool writes local state plus a feature-context file tied to the git remote, and explicitly states it never contacts the server. It omits what happens when a context already exists (overwrite vs. merge) and whether a remote-less checkout degrades gracefully.

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, front-loaded with the action and followed by effects, dependencies, and the trigger condition. Every sentence carries information, though the closing 'changes only local state' partly restates the earlier 'Writes local state'.

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?

One required parameter, no output schema, no annotations: the description supplies the side effects, downstream coupling, and invocation timing an agent needs. Only edge-case behavior on repeat invocation or missing git remote is left unstated.

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 single capabilityRef parameter is already documented in the schema; the description adds only the notion that the value becomes session-active and is inherited by later calls. That is useful context but not syntax or format guidance, so the baseline of 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?

States a specific verb and resource: 'Set the active capability reference for this session.' It also delineates scope ('for this session') and distinguishes itself from session-scoped siblings that merely read or refresh state, so an agent can identify it 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?

Explicitly says 'Call it when starting work on a feature', giving a clear trigger condition, and explains the downstream relationship to notify and propose_decision (they inherit it unless they pass their own capabilityRef). It stops short of naming when not to call it or how it interacts with refresh_decision_pack, but the usage context is unambiguous.

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