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

With no annotations, the description carries the full burden. 'Fetch' and 'full current state' imply a read-only operation, and 'Sessions are public' adds useful access context. However, it does not explicitly state that the tool has no side effects, how it handles invalid flock_ids, or any other failure behavior.

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 first sentence is concise and front-loaded with the core purpose. The second sentence adds genuinely useful context about session publicity and resumption. The third sentence, an open research question, is not actionable for tool selection or invocation and does not earn its place in a tool definition.

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 one-parameter read tool with no output schema, the description adequately enumerates what the response will contain: parameters, tick, latest metrics, and full parameter-change history. It also addresses accessibility via the public-session note. Minor gaps remain around error behavior and exact response shape, but nothing critical is missing.

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%: the only parameter, flock_id, is already documented as 'flock session id, as returned by flock_create'. The description adds no extra meaning about the parameter, 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?

The description clearly identifies a specific verb ('Fetch'), a specific resource ('a flock session'), and enumerates the contents (parameters, tick, latest metrics, parameter-change history). It is clear in isolation, but it does not explicitly distinguish itself from siblings like flock_timeline, so it falls short of full sibling differentiation.

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?

The statement 'Sessions are public — you can pick up where another agent left off' gives clear context for when this tool is useful: inspecting or resuming a session. It does not name alternative tools or explicitly state when not to use this tool, so it lacks exclusion guidance.

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