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

Goes well beyond the annotations by disclosing what actually happens to the data: a copy is stored at most 1080 px wide with metadata stripped, so the source link doesn't need to persist. It reinforces `idempotentHint: false` in plain language ('Not safe to repeat: every call stores a new copy') and states the constraint that private, local or sign-in-only URLs are refused — none of which appears in the schema or annotations.

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 return value, accepted formats, storage behavior and the repeat-safety warning each carry weight, and the core purpose is front-loaded in the first clause. The first sentence is long and carries a parenthetical, but no sentence is filler.

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 two-parameter mutation tool with no output schema, the description covers the return value, the format and accessibility constraints on the input, the post-import storage behavior, and the non-idempotency warning. An agent has everything needed to call it correctly and to avoid accidental duplicates.

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 the baseline is 3; the description adds real value by naming the accepted formats (JPG, PNG, WebP, GIF) and the public-https requirement, which are validation rules absent from the schema. It does not mention the optional `filename` parameter at all.

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 ('Adds one image to the Sociro media library from an https link') and immediately names what it returns (`media_file_id`). This distinguishes it from `list_media` (read) and `make_plan_post_image` (generation), so an agent can pick the right tool without opening a 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?

Gives clear positive selection criteria: use it for an image that is already online or that an image model produced with a link, and explains the downstream use by naming create_post's `media_file_ids` and cover usage. It does not explicitly contrast with `make_plan_post_image`, leaving that sibling routing implicit.

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