Get an agent session

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

Beyond readOnlyHint=true, the description discloses concrete failure semantics (404 for invisible sessions, 403 for an unviewable agent) and the full visibility model — UI-started sessions are private to the user and invisible to API keys, while task-run and incident sessions are workspace-visible. That is meaningful behavioral context the annotations cannot carry.

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?

Purpose is front-loaded in the first clause, and the subsequent sentences about 404/403 and visibility each carry distinct information. Slightly long for a simple fetch, but no sentence is redundant.

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?

An output schema exists, so return values need no explanation, and the description covers the error and permission model an agent needs to interpret failures. What remains unstated — whether the caller should prefer list_agent_sessions for discovery — is minor for a get-by-ID tool.

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 session_id and the X-Orchestra-Account-Id header are already documented, including the account/credential scoping rule. The description adds no parameter-level detail beyond the schema, so the 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?

States a specific verb and resource ('Get an agent session by ID'), so the operation is unambiguous. It does not, however, distinguish itself from siblings like list_agent_sessions, get_agent_session_history_messages, or create_agent_session beyond the singular 'by ID' framing.

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 implied rather than stated: the caller learns it needs a session ID and that visibility depends on how the session was started, but no alternative tool is named and no explicit when-to-use/when-not guidance is given. The visibility paragraph does function as de facto guidance about when the call will succeed.

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