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

Annotations already declare readOnlyHint/openWorldHint/destructiveHint=false, but the description adds real context beyond them: most actions read stored indexed context while exactly two (issues/read, code/read) reach GitHub live, and issues/read requires authentication with repoFullName + issueNumber. It doesn't cover rate limits or pagination/response shape, but the live-vs-stored distinction is genuinely informative.

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?

Front-loaded with the six domains, then live-vs-stored caveats, then exclusions and alternatives - a sensible order. It is dense but not padded; the main cost is that the long action enumeration partially duplicates the schema's action description, which is redundant but still aids action selection.

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 broad multi-domain read tool with an output schema and annotations already present, the description supplies what structured fields cannot: the live-vs-stored split, the ordering requirement before update_backlog, and explicit handoffs to the workflow/task-execution siblings. Nothing an agent needs to select the right domain/action 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 coverage is 100%, so baseline is 3, but the description goes further: it disambiguates which domain+action combinations exist, clarifies that issues/context, list and overlap use stored issue context while issues/read is live, and states that query accepts an ID, path, symbol, or skill name depending on domain. That is semantic guidance the schema's flat action enum does not convey.

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 states a concrete verb+resource ('Read project context') and immediately enumerates the six exact domains (code, system, issues, backlog, skills, stack), so an agent knows precisely the scope. It also names what it is not (workflow runs, task executions), separating it from siblings.

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?

It gives explicit routing rules: 'use backlog list/get actions to find existing epic and task IDs before calling update_backlog', and 'Not for workflow runs or task executions: use list_workflow_runs... get_workflow_run... get_task_execution...'. This is when-to-use, when-not-to-use, and named alternatives in one place.

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