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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description contributes the useful ownership scope (own account or session), but says nothing about pagination behavior beyond the limit cap, ordering, or what happens when no session_id is supplied.

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?

Two tight sentences with the ownership scope front-loaded and capabilities second; no filler. Slightly more compact phrasing could have folded the parenthetical about session into a clearer statement.

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?

With an output schema present, return values need no explanation, and all three optional parameters are fully documented in the schema. The only residual gap is the unstated behavior for authentication/session resolution ambiguity, which is minor for a read-only list 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 the schema already documents tag, limit (default 20, max 100) and session_id. The description only restates the tag filter and result count without adding format, matching, or session-precedence semantics, 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?

The description uses a specific verb and resource ("List short links") and scopes the result set to the authenticated user or current session, which separates it from get_link_info or get_link_analytics by implication. It does not explicitly name the sibling tools it should be preferred over, so it stops short of full disambiguation.

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 only implied: the agent can infer this is the browse-enumeration tool versus the single-link lookups offered by siblings, but there is no explicit "use this when..." statement, no exclusions, and no prerequisite note about authentication.

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